The technical development of wireless power transmission systems has been widely carried out recently. PTL 1 discloses a wireless power transmission system that includes a power transmitting apparatus having a power transmission mode in which power is transmitted to a power receiving apparatus and a detection mode in which, in the case where a voltage change is detected in the power transmission mode, whether the voltage change is caused by a foreign object or by a power receiving apparatus having moved is determined. PTL 1 describes that an influence on a foreign object is suppressed by making a voltage applied to a coil lower in the detection mode than in the power transmission mode. A technique has been developed in which one power transmitting apparatus performs wireless transmission of power to a plurality of power receiving apparatuses (PTL 2). PTL 2 discloses a configuration in which a power receiving apparatus is detected on the basis of an electric current that is generated when the power receiving apparatus exists in an electromagnetic field generated by a power transmission antenna.